Method for producing an improved die for use with a multi-element punch



Nov. 11, 1969 L. E. LIANDER 3,477,317

METHOD FOR PRODUCING AN IMPROVED DIE FOR USE WITH A MULTI-ELEMENT PUNCH Filed April 12, 1967 2 Sheets-Sheet l FIG.1 I I l F /f /.5e 22 12 A I I a 7 ii +11..- i" :E V /////////////%W/V /F 34 7 s2 v 42 I I INVEQITOR LEONARD E. UANDER ATTORNEY 1969 L. E. LIANDER 77,317

METHOD FOR PRODUCING AN IMPROVED DIE FOR USE WITH A MULTI-ELEMENI PUNCH Filed. April 12. 1967 2 Sheets-Sheet 2 FIG. 3

G) G) (D (D G G) @i- Q G) G) (D G G (9 C) G) 6) 6 United States Patent 3,477,317 METHOD FOR PRODUCING AN IMPROVED DIE FOR USE WITH A MULTI-ELEMENT PUNCH Leonard E. Liander, Fishkill, N.Y., assignor to International Business Machines Corporation, Armonk, NY, a corporation of New York Filed Apr. 12, 1967, Ser. No. 630,340 Int. Cl. B21k 5/20; B26d 5/08; B26f 1/14 US. Cl. 76-107 6 (Ilanns ABSTRACT OF THE DISCLOSURE The method comprises boring holes of a diameter greater than the diameter of respective punch elements through a backup plate at locations which correspond to the locations of the respective punch elements; positioning said backup plate with respect to said punch elements so that said bored holes and respective punch elements are coaxial; attaching a soft, wear resistant material to the punch element facing surface of said backup plate and operating said punch elements to simultaneously punch holes through said soft material, each hole being within the area of a respective bore hole in said backup plate.

spective positions of the punch elements. Thus, any material which is to be punched is placed on the die, the punch operated and the punch elements thereof punch through the material and into the correctly located openings in the die. This type of die has served its purpose very well, especially since the die material is usually hard steel. However, in the present miniaturization direction of some technologies, the above mentioned conventional approach to die making has proved to be impractical. For example, in connection with the present invention, a matrix of holes having diameters in the ten-thousandths of an inch range are to be simultaneously punched at precise locations with respect to one another. It will be appreciated, that the least misalignment of die holes will require the making of a new die since it would produce v breakage of the fragile punches. Due to the precise machining problem involved in locating and boring the holes, the die becomes quite expensive. It has also been found, that the material to be punched if at all abrasive causes excessive wear of the die. It is also very difficult to make a die which is an exact duplicate of a die to be replaced because of boring runout problems.

Accordingly, it is the main object of the present invention to provide a method for making a die in which there is no hole misalignment with respect to the punch elements.

It is another object of the present invention to provide a die which is highly wear-resistant to abrasive materials. It is a further object of the present invention to provide a die which is an exact duplicate of a replaced die.

It is yet a further object of the invention to provide a die which practically eliminates punch element breakage.

Briefly, the invention is an improved method for making a die for use with a multi-element punch comprising the steps of: locating positions on a backup plate each of which corresponds to the position of a respective punch element; boring holes at said positions of a diameter 3,477,317 Patented Nov. 11, 1969 larger than the diameter of the punch elements; attaching a relatively soft material to one side of said backup plate and positioning the backup plate so that the soft material faces the punch elements and each of the holes is aligned with a respective punch element; and operating the punch so as to punch holes in the soft material die over the holes in the backup plate thereby producing a soft material die in which the holes are exactly aligned with the respective punch elements.

The foregoing and other objects, features and advantages of the invention will be apparent from the following and more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.

FIG. 1 is a vertical cross sectional diagram of the punch apparatus and soft, wear resistant material in place for punching.

FIG. 2 shows a vertical cross sectional diagram of the punch apparatus after being operated to punch holes in the soft wear-resistant material.

FIG. 3 is a sectional view along the line 3-3 of FIG. 2 which shows the matrix arrangement of the punch elements and the large clearance space for the punch elements in the holes in the backup plate.

Referring to FIG. 1, there is shown a cross sectional view of a punch apparatus which could be utilized in making the improved die of the instant invention. The punch apparatus consists mainly of a matrix of punch elements 12, each of which is precisely located with respect to the others to produce, when operated, a precisely located plurality of holes in a matrix. The punch elements 12 are held in position in holes in a punch holder 14. The punch elements 12 each consist of an elongated shank 16 which ends in a tapered tip 18 of a very small diameter. The shanks 16 of the punch elements 12 are each topped by a head 22 of a greater diameter than the shanks 16 which limits the lengthwise positioning of the punch elements 12. Spring loaded to the punch element holder 14 is a stripper plate 24 which has holes therein which correspond to the position of the holes in the punch element holder 14. As can be seen in FIG. 1, the punch elements 12 are inserted in the holes in the top of the holder element 14 and extend downwardly therethrough into the holes in the stripper plate 24. The punch elements .12 do not extend fully through the stripper plate 24 but end a short distance from the bottom thereof. The punch apparatus also has a backup plate 26 located parallel to the bottom of the stripper plate 24 a short distance therefrom. The material 28 to be made into a die in connection with this invention is shown attached to the backup plate 26 in the space between the stripper plate 24 and the backup plate 26. In this particular embodiment, a further backup plate 32 abuts the bottom of the previously mentioned backup plate 26. The further backup plate 32 has vacuum passages 34 therein.

FIG. 2 is a further view of the punch apparatus, shown in FIG. 1, showing the apparatus in the operated position. As can be seen, the operating force is exerted downwardly on the punch element holder 14 via a backing plate 36. In operation the stripper plate 24 contacts the material 28 to be punched in the downward movement of the punch apparatus. When the stripper plate 24 stops, the punch elements 12 held by the punch holder 14 continue their downward travel and extend beyond the end of the stripper plate 24 and pass through the material 28. Springs 38 located between the punch holder 14 and stripper plate 24 are compressed by the downward motion of the punch holder 14 toward the stopped stripper plate 24 thereby providing a somewhat controlled shock free movement between the punch holder 14 and stripper plate 24. Of course, the operation continues and the punch apparatus is raised to its initial position shown in FIG. 1.

FIG. 3, which is a view along the line 33 of FIG. 2, shows the matrix arrangement of the punch elements 12. To provide an idea of the actual sizes and distances involved in the apparatus for carrying out the method of the instant invention, various examples of dimensions are given. The holes punched in the soft plastic materials are spaced from one another by a distance d equal to .03185 inch. Actually, apparatus for punching holes of such close spacing and small dimensions is used in connection with manufacturing small semi-conductor modules for electronic equipment. In the particular embodiment being described, the punch element tip 18 diameter is .0051 inch. Punch elements as small as .003 inch in diameter have been used.

Considering now the method for producing the improved die 28 for use with the multi-element punch apparatus just described, holes 42 are spotted and bored in a backup plate 26 of a diameter larger than the diameter of the tapered tip 18 of the punch elements 12. Each hole 42 is precisely located to correspond with the location of a respective punch element 12. In the example, where the tapered tip 18 of the punch element 12 is .0051 inch in diameter, the holes 42 bored in the backup plate 26 are .008 inch in diameter. Thus, this gives a hole 42 which is considerably larger than the punch element tip 18 diameter. A thin sheet of a soft wear resistant material 28 is located on the upper working surface of the backup plate 26. The material 28 can be plastic such as a vinyl plastic. The material 28 can be attached to the backup plate 26 in several ways. For example, a double sided adhesive could be used or preferably a vacuum system could be used to hold the thin sheet of material 28 in position on the backup plate 26. As can be seen from FIGS. 1 and 2 such a vacuum system is utilized in that embodiment. The vacuum is applied through the vacuum ports 34 which connect to the holes 42 bored in the backup plate 26 just mentioned, thereby, providing the necessary vacuum suction to hold the plastic material 28 in position thereon. The backup plate 26 is positioned to line up the holes 42 therein with the punch elements. The punch apparatus is operated, as previously described, to punch the holes in the plastic material 28. The punch element tips 18 extend through the plastic material into the holes 42 in the backup plate 26, as shown in FIG. 2. Since the holes 42 in the backup plate 26 are of a considerably greater diameter than the punch element tips 18, there is no problem with wear or breakage of the punch element tips 18 because of small misalignments of the holes 42 with the punch elements 12. It will also be appreciated, that the vacuum system arrangement of holding the plastic material 28 onto the backup plate 26 also provides suction and a passage for automatically removing any of the plastic material that may be punched out as a result of the punching operation and thus, the various punchout elements will not accumulate and cause any obstruction to the punch elements 12. It will be appreciated, that the plastic sheet of material 28 now has holes located therein which are precisely aligned with the punch elements 12 and which plastic material is backed up by a backing plate 26 having holes 42 of a larger diameter coaxial with the holes therein.

The punched plastic material 28 is a die and the material in which holes are to be punched is now located in the apparatus between the punch elements 12 and the plastic material die 28. When the punch apparatus is operated, as previously described, the sheet material (not shown) inserted between the punch elements and the plastic material die will have the precisely located holes punched therein. Many of the materials which are to be punched are abrasive and accordingly will produce wear on the plastic material die 28. For example, one of the materials in which such holes are to be punched is known as zircon alkaline earth porcelain green sheet. Of course, the thickness of material is limited, due to the fragile nature and sizes of the punch element tips 18. Zircon alkaline earth porcelain green sheet .007 to 0.12 inch thick has been successfully punched. As the plastic material die 28 wears because of the abrasive nature of the materials being punched, a new sheet of plastic material can be substituted for the worn plastic material die 28, and the necessary holes punched therein by the punching apparatus as was done for the original plastic material die 28. Thus, it will be appreciated that this method provides an easily replaceable die which reduces punch element tip breakage, which needs no precise machining and which considerably reduces the cost and time involved in die making.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and detail may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. An improved method for making a die for use with a multi-element punch for simultaneously punching a plurality of small diameter holes in a sheet of material, comprising the steps of:

locating positions on the working face of a backup plate each of which corresponds to the position of a respective punch element,

forming holes at said positions of a diameter larger than the diameter of the punch elements,

attaching a relatively soft plastic material to the working face of said backup plate,

positioning said backup plate so that said soft plastic material faces said punch elements and each of said plurality of holes is aligned with a respective punch element,

and operating said punch so as to punch holes in said soft plastic material over said holes in said backup plate, thereby producing a soft plastic material die in which the holes are exactly aligned with the respective punch elements.

2. The method according to claim 1, wherein said soft plastic material is attached to said backup plate by a twosided adhesive tape.

3. The method according to claim 1, wherein said relatively soft plastic material is attached to said backup plate by a vacuum applied through the openings in the backup plate, said vacuum also removing the portion of soft plastic material punched out by said punch elements.

4. The method according to claim 1, wherein said punch elements are .003 to .0051 inch in diameter.

5. The method according to claim 1 wherein the bored holes in said backing plate are approximately .008 inch in diameter.

6. The method according to claim 1, wherein said holes in said die are located from one another at a distance of approximately .03185 inch.

References Cited UNITED STATES PATENTS BERNARD STICKNEY, Primary Examiner US. Cl. X.R. 83-620, 660, 687 

